Perhaps he was referring to the Planetary Resources, Inc. proposal to bring a small asteroid to lunar orbit. But another possibility is a mission to near Earth asteroids that can be accomplished in about a month round trip travel time. See the table of NEO's here:

Select max delta-v <= 12 km/s, visit time => 8 days, unlimited visual magnitude, the H parameter, and unlimited orbital uncertainty, the OCC parameter. Then there are several asteroids at 26, 34, and 42 day travel times, including stay times at or above 8 days. If you subtract off that stay time to make it only a day or so then the round trip travel time will be in the range of a month or so. This could serve as an intermediate step for BEO missions between the Apollo missions at max. 12 days and a Mars mission at 6 months one-way travel time.

Bob Clark

_________________Nanotechnology now can produce the space elevator and private orbital launchers. It now also makes possible the long desired 'flying cars'. This crowdfunding campaign is to prove it:

What could a manned mission to a NEO accomplish in a week than an unmanned exploration platform like the Curiosity MSL could accomplish with a much longer to indefinite duration mission?

What justifies the order of magnitude higher cost and risk of doing these manned missions as envisioned (Apollo replicas)?

There needs to be a rational business case or at least practical reasons otherwise it's going to be another unsustainable flash in the pan stunt like the Apollo program. Also, I think our approach is tragically wrong. Instead of self-contained one-shot missions, we should be building reusable in-orbit space transportation assets even if the upfront costs and time are higher. Otherwise it's; "OOoo! look we went to the Moon, and then fifty years later we visited an asteroid. Then another twenty years after that we went to Mars for a while."

If we go extinct some time after that, alien archeologists will look at the evidence and decide that "humans dabbled in space travel, but did not seem to be interested in actually expanding beyond their one planet."

Argues the first version of the SLS will have a 95+ mT payload capacity, not just 70 mT, enough to do a manned lunar landing by its first launch in 2017. And moreover addition of a small propulsive stage a fraction of the size of the upper stage on an EELV can raise the payload to 130 mT at minimal additional cost.

Bob Clark

_________________Nanotechnology now can produce the space elevator and private orbital launchers. It now also makes possible the long desired 'flying cars'. This crowdfunding campaign is to prove it:

What could a manned mission to a NEO accomplish in a week than an unmanned exploration platform like the Curiosity MSL could accomplish with a much longer to indefinite duration mission?

What justifies the order of magnitude higher cost and risk of doing these manned missions as envisioned (Apollo replicas)?

There needs to be a rational business case or at least practical reasons otherwise it's going to be another unsustainable flash in the pan stunt like the Apollo program. Also, I think our approach is tragically wrong. Instead of self-contained one-shot missions, we should be building reusable in-orbit space transportation assets even if the upfront costs and time are higher. Otherwise it's; "OOoo! look we went to the Moon, and then fifty years later we visited an asteroid. Then another twenty years after that we went to Mars for a while."

If we go extinct some time after that, alien archeologists will look at the evidence and decide that "humans dabbled in space travel, but did not seem to be interested in actually expanding beyond their one planet."

/rant

I would hope that a manned NEO expedition would get us enough information to help us decide if mining NEO's or going back to the Moon to mine is the best way to bootstrap a solar system wide civilisation a lot can be done with semi autonomous waldoed probes like Curiosity but it will be a quite few years yet before they get to the level of flexibility of a well trained smart human. But i agree that a lot could be offloaded to probes it is just a question of working out the best balance. And another argument is that as it could still need a lot of public funding,most of the public are more likely to be engaged with a human running a mission than a robot even if it is not quite as efficient in some ways.

_________________Someone has to tilt at windmills.So that we know what to do when the real giants come!!!!

Humans expand until they can't, and then they start to die off, we need to find balance, we currently waste huge resources on golden toilet seats for rich ....four letter words...

Space is the next step in the evaluation of man and the evolution of man, the next Darwin, the reason the we could have for existing, to explore, to refine.....

what happens if we don't branch out? destroying 1/1 human colonies, with any device/impact/x-ray burst/name itit is far less likely to hit people all over space, then to hit all of the people where they are now.

We need to be more then a blip, we need to do things because it fills a need, not for money, money and religion is the only thing holding us back now, technology could solve all of our real problems, the ones we have now are contrived, Food is plentiful, were there are no people..... Water is clean....where this is no people....... Space is open and free.... until we have people in it telling each other that it is there space....

_________________Let not the bindings of society hold you back from improving it.... the masses follow where the bold explore.

The problem is that what we are currently doing is not "branching out". All of our space activity from the 50's up to the SLS is inwardly or internally motivated. Cold-war gamesmanship, terrestrial applications, and political pandering. To borrow a cliche, "We are doing it wrong".

Yes, space is the answer to all of our needs and questions, the problem is that we as a species are not rising to that challenge. There are glimmers from the likes of Space X, Planetary Resources, and even Mars One, but they are almost a sad joke compared to the optimism of the early "Space Age".

I WANT MONEY!!! Heck if I had the money Richard Branson or Elon Musk does (or did) I'd be in space too. I may not know every detail of a good launch system but I sure can tell a good idea when I see it and I'm not at all against using other peoples ideas if they're better than mine and I have a legal right.

At an empty tank mass of 26.5 metric tons(mT) this would be well within thecapability of the 70 mT SLS of getting this to LEO, as at least an outer hullof a space station. Note for this purpose we could remove the ET bulkheads soit would even weigh less than this. This would have a volume two and a half times that of the ISS. And at the 130 mT payload capacity of the later SLS version, using Centaurstyle in-space stages we could even transport this to the Moon.

Bob Clark

_________________Nanotechnology now can produce the space elevator and private orbital launchers. It now also makes possible the long desired 'flying cars'. This crowdfunding campaign is to prove it:

I do hope they take the potential seriously this time and allocate some money/mass to carry the tanks to orbit. I understand the budgetary,engineering, and logistical problems than prevented NASA from using the STS ETs, but now they have a clean sheet and enough budget to incorporate the opportunity if they choose.

Rand Simberg suggested to me the reason why NASA keeps saying the Block 1 version of the SLS will only have a payload of 70 mT, same as for the Block 0, is to maintain the pork of the expensive upper stage.

Citing ITAR for the current Block 1 version makes no sense since they were willing to give the 70 mT capability of the Block 0. Also, another conclusion you can draw from this is the payload capability of the Block 1 will not really just be 70 mT otherwise they would have just given this number again for the FOIA request.

My guess about why NASA kept giving the 70 mT number of the Block 0 and not the real number of the Block 1 was because they just didn't take the time and effort to do the analysis on the capability of the upgraded rocket. It was easier to just cite 70 mT because they knew the new version would at least reach this. But now I'm beginning to think perhaps Simberg was right.

Certainly the cite of the ITAR restrictions just raises more questions.

Bob Clark

_________________Nanotechnology now can produce the space elevator and private orbital launchers. It now also makes possible the long desired 'flying cars'. This crowdfunding campaign is to prove it:

Rand Simberg suggested to me the reason why NASA keeps saying the Block 1 version of the SLS will only have a payload of 70 mT, same as for the Block 0, is to maintain the pork of the expensive upper stage.

Citing ITAR for the current Block 1 version makes no sense since they were willing to give the 70 mT capability of the Block 0. Also, another conclusion you can draw from this is the payload capability of the Block 1 will not really just be 70 mT otherwise they would have just given this number again for the FOIA request.

My guess about why NASA kept giving the 70 mT number of the Block 0 and not the real number of the Block 1 was because they just didn't take the time and effort to do the analysis on the capability of the upgraded rocket. It was easier to just cite 70 mT because they knew the new version would at least reach this. But now I'm beginning to think perhaps Simberg was right.

Certainly the cite of the ITAR restrictions just raises more questions.

Bob Clark

I've been informed by knowledgeable individuals that the Block I SLS likely will have greater payload than just 70 mT, though not as high as what I was estimating. The problem is with designing any new rocket there is always weight growth so you put some error bars around your mass estimates. NASA frequently takes a conservative approach to those mass growth estimates which can drive down your payload estimates. In any case I don't believe there was anything untoward in the decision not to release the SLS specifications. I think as the SLS comes closer to completion, hopefully by 2017, more accurate numbers for its capabilities will be released. However, it should be noted that many industry insiders do not believe the final Block II version of the SLS will ever fly, because of its long time lag, 20 years, and high cost. Then I think it would be prudent for NASA to investigate weight saving techniques on the Block I SLS core to maximize its payload capability. Then even if the Block II is never completed we can still perform BEO missions even with just the Block I scheduled to launch in 2017.